When two or more components are assembled into a single unit, a retaining structure is needed to prevent separation especially when the assembled components are in a rotating device such as a transmission. A common retention device for such assemblies is a retaining ring that engages in a groove formed in the radially outer member of the assembly. This method of assembly requires sufficient axial space to accommodate the groove portion of the outer member. Thus the assembly length is increased in the range of 1/4 to 1/2 of an inch due to the presence of the retaining ring.
When the retaining ring is disposed in a groove formed in the inner member, the centrifugal forces associated with large rotating bodies can cause the ring to disengage the groove. With such assemblies, special locking members are installed at assembly, thereby adding to the cost and assembly time.
Other assembly methods, such as welding or brazing, have also been used. These methods generally add cost and increased handling time for the assembly and also make the disassembly thereof difficult. Press fit and staking operations have been used also. These operations generally require tighter machining tolerances and pressing equipment to achieve the final assembly.